In current hybrid cloud backup, data of a virtual machine (VM) or a physical machine (PM) of a non-public-cloud data center is backed up locally in a unit of a volume. Alternatively, after being backed up locally, the data is then remotely replicated to a cost-effective storage device in a cloud data center, and is restored to a VM (which may also be referred to as a cloud host) of the cloud data center using a backup server in the cloud data center in order to achieve purposes of redundancy and data backup.
Backup data generated in each backup is referred to as a backup replica. The backup replica includes multiple backup data objects. An object is a basic unit of data storage in an object storage technology. One object is a combination of file data and a group of attribute information (metadata). When backup software backs up, in a form of an object, the VM/PM data to the storage device, the VM/PM data is stored in a form of a backup replica. However, a format type of data that can be registered with the cloud data center is a data format of an image object. Therefore, the backup server needs to create, on the storage device and based on the backup replica, an image object that is corresponding to the backup replica and that can be registered with the cloud data center. Herein, an image means an image in the cloud data center. An image object is an object in the cloud data center that is compatible with the cloud data center and that can be used to create a VM and a disk of the VM.
However, in a procedure of creating the image object on the storage device of the cloud data center, in an aspect, because the backup server needs to first read the backup replica from the storage device and then deliver a write operation request to the storage device to form the image object, a lot of time has been spent because of a large amount of input-output (IO) before a cloud disk of the VM is created. In another aspect, because a user's storage space on the storage device needs to be used for creating the image object on the storage device, cloud data center storage costs of the user increase.